Attachment plug



Filed April 20. 1928 Patented Sept. 3, 1929.

UNITED-STATES PA ENTYQFFICE. I

JOHN 'A. FRETZ, OF PHILADELPHIA, PENNSYLVANIA.

Armcnmnnr PL G; 1

Application an April 20,

My invention relates to a new and useful improvementin an attachmentplug such as are designed particularly for use with elec i;

trical conductor cords or Wires forconnecting 5 the conductor cord withan outlet socket or the like whereby electriecurrent may be supplied toan electric appliance such; as lamps, fans and irons, and one of theprincipal objects of this invention is to provide for'placing the plugin a screw socket after twisting .elec}.

trical conductor cord. f

Another object ofthe invention to pro;

videan attachment "plug consistingfof a core which lncludes a base andstem, contact mem: bers'carrled 'by'sald core,,a barrel revolublymounted on the core and includingathreaded. L head, a portionofwhichcoacts withone of the contact members an dhaa screw threadedengagement with the, core and "corn tact with the other of thecon'tac'tfmembers" but insulated from. the threaded head of; the barrel,said screw holding the barrel in place.

A further object ofthe,inventionislto pro vide uniqueconnectionsbe'tw'een the poles of the attachment plug and the wiresoft-he elec I trical conductor cordleading therefrom. A still furtherobject of my invention is I to providea device ofthis character which isf adaptableto different typesof attachment;

consists in the details of vconstruciztion and combination of elementshereinafter setforth and then specifically designated bythe claims.

stand how to use andmake the same, will describe its construction indetail -refe'rjring by numerals to the accompanying drawings:

0 forming a part of this application,in;which:

1, is an upper or outerend view of an of a modified form of the device.

plugs such as separable and inseparable'ones i With these ends in View,this'invention I In order that; those; skilled in the art' to which thisinvention. appertains may under-j,

' Fig. 7, is a side elevation partly section 1928. Serial 118. 271,452.

Fig.8, is 'an'upper or outer end view of the "core used connection witheither of the forms.

In carryinglout my invention as'h'erein embodied, particular referencebeing bad to Figs. l to' 6 i'nclusiveand 8, the numeral 10 representsthe core'as a wholeincludinga base 11 and a stem 12, the latter being ofsmaller cross sectional area than the base to" .provlde' a shoulder 13for a purpose to be later described. y t

Thestem ofthe core has two curved surfaces 14 separated bytwolongitudinal channels 1 5 and through the base of thejcore aretwo'holesf16 in endwise alignment with the channelsf15 and practicallyform extensions thereof. The upperend of the shank is re-' duced insizeto form aneck 17 which may be amount 'of resiliency to insure contactwith certain elements'to' be later described and on theupper or outerend of said strip is formed a curved collar 19,,the ends of which areseparated sufficiently to p permit of ,flexin'g or moving withoutbinding and this collar part 1y surrounds the neck 17. y I

'The inner or lower end of the contactv strip or member projectsintofthe' hole l6fin the" corebase'which is inalignment with thechannelin which said strip is mounted and the inner terminal' of saidstrip is bent back upon itself to'form a tongueQO which will engage oneof the walls of the hole and tend to force the lower end of the contactstrip toward the opposite wallor toward the center of the core,thusproviding the desired tension to hold thestrip in contact withtheusual terminals (not shown) of the ordinary separable mem ber 21 ofattachment plugs or the like. This contact strip isfheld in place byasuitable fastening device 22 such as a-screw located intermediateitsends and at some point below such. fastening device, the inner end of ofthe same diameter as the distance between the two'channelsfwhich aredirectly opposite each otherl I I Within oneof the channels is mounted acontact'strip or member 1810f suitable elec a I i v trical conducting,metal havlng a certain:

thestrip-isfbent outward or away from the, f

wall to which the strip is fastened. I

- Asecond contact strip or member 23 also of resilient materialismounted inthe other ponent: parts :intplace whilelpermitting ma a'ameterequal to that across the core shank be- .end wall 30" 'from'thecenter of whichextends base,

gages the lip 26 of the contact strip 23, th1is k providing forconnection with the oth'ersidei a base,

construction .withthe exception, thaththe con-. 'tact membersyl8. land23 terminate short of;-

channel with the, inner end projecting into balance of theparts of theattachment plug the other hole 16 in the core base and said illustratedin Fig. 7. strip 23 is held in place by a suitable fasten- In practice,when it is desired to connect ing device 2 lsuch' as a screw theattachment plug with a socket'or similar Like the other contact strip18, the lower "outletysaid "attachment plug is inserted in end of thecontact strip 23 is bentaway from the'socket and the barrel 28 revolvedso that the wall to which itisfastened and also hasxa the'screwthreadedhead-29::will screw into its inner or lower terminal bent backupon the socket and since said barrel revolves indeitself to provide atongue 25 which engages al pend'eii-t of the core, the electricalconductor wall of the hole in which it is mounted and cord or Wires willnot be twisted during the therefore tends to force the lowerend' of saidoperation." strips toward the center of the ,core, but the Itmight bewell to mention at this time that upper end ofsaid' strip 23.. is,bntiatsubs'tan-v o th'ecore and barrel'are of suitable insulatingtially right angles t the body thereof, tormaterialtoeliminatethepossibility ofashort" form, a :lip 26 whichprojectsi intouatrans- "circuitf I verse aperture 27 into thelsha nko'of the core sO-fcourse'I donot wish'to be limited to the i adjacent the upper'orouter endof thelatten exact details 50f construction as herein' shown";On .7 the stem of the, core isrrevolubl'y' as these may bevariedwithinthe'lifnits of mounted a barrel 28 having an internal dif theappendedclaims'withoutdeparting the spirit of'inyn invention. a tweenthe two curved surfaces -145 andjwith. Having husfullyf descri the inneror lower end or said barrel riesting'j t l 'laim'aSIIeWfl-nd useful i onthe shoulder 13 ofithe score-base. 1. An attachment plugin luding a O B'11*-'- v The upper end of thebarrelcarriesfa screw 1 sisting of a3base'having holes therethroughfa threaded metal head. 29': fixed totsaidbarrel 'q'fshank projecting f rom thebase and including by a suitablefasteningdevice. 80suchfasa o two curved surfaces separated by'apair'of" screw, pin .orthe like ,and in addition tolthe; screw threadedpart,-saidflhead ,includesana in endwi'se: alignment with ftthe"hole's'in the" v and a neck at-the" outer end of the shank-, an inwardlyprojecting circular flange, 31 ofj a contact member, inloneofthechannelsand efi the properv diameter to enclo'sevthecollar.llljhaving a collar capable offle'irion-partially f of the contact strip18 and hold said-collar surroundingxthe core'neck, anothercontact'fundertGDSlOIllD orderto insure. a positive member mounted in"the;'otl1'er" channel and contact between said flange andcollanthus.provided withfla "l p, pro ecting nto a trans-" providing throughthehead29 itsiflange 31,; verse aperture in the core shank," a barrel thecollar1 9 and the body oithescontact stripf rotatably mounted on the'core and engaging X 18. a connection, withonesidelofan electric. thecurved surfaces" for. bear ngs a"screur circuitf r i threaded head ofelectrical conductivity" About. the .neck 17;, time core is mountedmounted on one end of;the barrel and providan insulating washer. 32which rest-smpon the t ed with an inwardly projecting circular flange 5end wall '80. Ofrtllfillhd- 29z and s aiilwasllr fo'rcoactionwithithecollar'of thefirst-m'enis held in place by a suitablecap screw .33.? tioned -contact: strip; an insulating "washer-1surmounting gthe' hea'd,"fandfa screw having threaded "engagement withthei outer end of the core shankfand projecting into engagementwith tlrother'contactstri and coacting with the washento'hdld'it and-t e barrelwith the head thereonin place: r

2.In.,an attachment pl g, a core includingi a shank of smaller'diameterthansai ofthe electrical circuit. s 7 base, said'ishank'having apairfof'oppo'sitely InlFig. ,7 Ihaveshown identically'tli'esame disposedlbngitudina'l channels aligning- W t principle I utilized in, c theabove vdescribed hole'sythrouglrfthe base and iui'therprovi'ded with atransverse "aperture communicatingwith one ofthechannelsandzalongitudinal thle'loweror inner endofthelcoreand theffase hole in-thouter'end communicating with the which therefore holds thebarrel anditscom= tation, thereof .andvthe body of said, screw is screwed into thethreaded hole er commma- .1 eating with theaperture 27 so thatv whensaidscrew is properly, infiplace,.itsinnerrendrenv tenlng devices 22.and 24are utilized as bind; aperture, a contact 'membeitmounted inone ingscrewsso that the conductors or'o wir'es ofof the channels and havinga,portionproject' an electrical :OOICl areinserted .thkroughthe. ing'into'the aperture, anoth'e'r contact memholes 16 of the. core base andfastened inplace ber mounted in the other'cha'nn'el and having by thescrews22v and247 insteadrofthe wires a portion-disposed adjacent theouter end of beingconnected withthe separablemember said shank, a barrelsurrounding the shank, 2las in the case of the previously' describedahead carried by* sa1d barrel-and provided form. The rest of thepartsbe'ing similar, I with means forcontact with thatportiomof haveused the same numbers to designate the the second-named contact strlpad]acent the bedmy invent-ion, I

soppositely disposed channels, the 'latter being into the holes in thecore base and have their 1 terminals bent back upon themselves forengagement with Walls of said holes to provide spring action at theinner ends of said contact strips.

In testimony whereof, I have hereunto af- 1 fixed my signature.

JOHN A. FRETZ.

